Supporting tube



FIG. 1 is a perspective view of a supporting tube showing my new design;

FIG. 2 is another perspective view thereof;

FIG. 3 is a front view thereof, the rear view being identical therewith;

FIG. 4 is a left side view thereof, the right side being identical therewith;

FIG. 5 is a top view thereof, the bottom view being identical therewith;

FIG. 6 is a cross section view showing a section taken along line 6-6 of FIG. 4 ; and,

FIG. 7 is an enlarged view of detail A taken from FIG. 6 .

The broken lines shown in FIGS. 1-4 illustrate environment and form no part of the claimed design. The dash-dot lines shown in FIGS. 1-4 represent the bounds of the claim and form no part of the claimed design. The stippling indicates a contrast in appearance and forms no part of the claimed design.

The supporting tube is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design. 

CLAIM The ornamental design for a supporting tube, as shown and described. 